Serialized Data (CSV)

[z0lo13]

from PrintPreview component as well as from printer behaviour, i can see that every page of serialized data is printed in a separate job. However Niimbot app does print everything in one job.

Do you have an idea of how do they do that?

As i also see you have the following comment:

niimblue/src/lib/PrintPreview.svelte

Line 92 in 19abea4

// do it in a stupid way (multi-page print not finished yet)

[MultiMote]

Hi! As I understand it, the generic process is:

SetDensity/SetLabelType/etc.
PrintStart
# repeat ↓↓↓↓↓↓↓
PageStart
SetPageSize
PrintEmptyRow | PrintBitmapRow | PrintBitmapRowIndexed
PageEnd
# repeat ↑↑↑↑↑↑↑
(status wait packets)
PrintEnd

niimbluelib already supports multi-page prints so onPrint function may look like this:

const onPrint = async () => {
  printState = "sending";
  error = "";
  $printerClient.stopHeartbeat();

  const printTask = $printerClient.abstraction.newPrintTask(printTaskName, {
    totalPages: pagesTotal * quantity,
    density,
    labelType,
    statusPollIntervalMs: 100,
    statusTimeoutMs: 8_000,
  });

  const listener = (e: PrintProgressEvent) => {
    printProgress = Math.floor((e.page / quantity) * ((e.pagePrintProgress + e.pageFeedProgress) / 2));
  };

  $printerClient.on("printprogress", listener);

  try {
    await printTask.printInit();

    printState = "printing";

    for (let curPage = 0; curPage < pagesTotal; curPage++) {
      page = curPage;
      console.log("Printing page", page);
      await generatePreviewData(page);
      const encoded: EncodedImage = ImageEncoder.encodeCanvas(previewCanvas, labelProps.printDirection);
      await printTask.printPage(encoded, quantity);
    }

    await printTask.waitForFinished();
    await endPrint();
  } catch (e) {
    error = `${e}`;
    console.error(e);
  }

  $printerClient.off("printprogress", listener);
  printState = "idle";
  $printerClient.startHeartbeat();

  if (printNow && !error) {
    modal.hide();
  }
};

I will work on this later, currently I've decided to take a break 🙂

[z0lo13]

@MultiMote
Thank you for the example, it works, with a one exception:

I am using B1 printer, and from the following line inside of packet_generator.js, i assume it is an expected bahaviour:

B1 behavior: when {@link totalPages} > 1 after {@link pageEnd} paper stops at printhead position and waits for next page.
When last page ({@link totalPages}) printed paper moved further.

However when using the niimbot app it is not stopping and printing straight away non stop. Is there something i can help investigating this behaviour?

[MultiMote]

I'll look at the original traffic capture. How did you run multi-page printing from the original application?

UPD: Tried to print xlsx data from desktop app - there is delay between pages,
UPD2: Mobile app prints without delay, I will check it.

[MultiMote]

b1_multipage_android.log

b1_multipage_desktop.log

You can visualize it here: https://dev.mmote.ru/niim-parser/

[MultiMote]

I checked onPrint code again and it prints without delays. I think is bottleneck here is the packet transfer rate.

[z0lo13]

@MultiMote for me it print with delays. I forgot to mention i am on capacitor enviroment. In the web it also prints with delays.